Huntington’s disease (HD) is a dominantly inherited neurodegenerative disorder characterized by a combination of motor symptoms, cognitive decline, and psychiatric manifestations. While clinical diagnosis primarily relies on the identification of motor symptoms, it is widely acknowledged that various nonmotor symptoms may manifest even one or two decades before the onset of motor dysfunction. A significant challenge in HD management stems from the absence of reliable biomarkers that facilitate early diagnosis, enable tracking of disease progression, and assess treatment efficacy. The identification of clinical and imaging prognostic markers in presymptomatic individuals holds great promise, providing a critical window for potential early interventions. Cognitive impairment is among the symptoms that manifest years before a formal diagnosis, emphasizing the need for enhanced knowledge and sensitive detection methods. This chapter delves into the current landscape of biomarker research in HD, shedding light on promising candidates and discussing their potential implications for clinical practice, with a particular focus on cognitive biological markers. Brain and retinal imaging techniques; molecular markers in cerebrospinal fluid, blood, and other fluids; and inflammatory markers are overviewed.